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Related papers: Protostellar Turbulence Driven by Collimated Outfl…

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(Abridged) The formation of molecular clouds (MCs) from the diffuse interstellar gas appears to be a necessary step for star formation, as young stars invariably occur within them. However, the mechanisms controlling the formation of MCs…

Astrophysics · Physics 2007-11-26 P. Hennebelle , M. -M. Mac Low , E. Vazquez-Semadeni

The evolution of collapsing clouds embedded in different star-forming environments is investigated using three-dimensional non-ideal magnetohydrodynamics simulations considering different cloud metallicities ($Z/\thinspace Z_\odot$ = 0,…

Solar and Stellar Astrophysics · Physics 2019-04-24 Koki Higuchi , Masahiro N. Machida , Hajime Susa

We discuss the role of turbulence in cloud and star formation, as observed in numerical simulations of the interstellar medium. Turbulent compression at the interfaces of colliding gas streams is responsible for the formation of…

Astrophysics · Physics 2007-05-23 E. Vazquez-Semadeni , T. Passot , A. Pouquet

We investigate the formation of protostellar clusters during the collapse of dense molecular cloud cores with a focus on the evolution of potential and kinetic energy, the degree of substructure, and the early phase of mass segregation. Our…

Solar and Stellar Astrophysics · Physics 2015-06-03 Philipp Girichidis , Christoph Federrath , Richard Allison , Robi Banerjee , Ralf Klessen

We review the properties of turbulent molecular clouds (MCs), focusing on the physical processes that influence star formation (SF). MC formation appears to occur during large-scale compression of the diffuse ISM driven by supernovae,…

Astrophysics · Physics 2007-05-23 J. Ballesteros-Paredes , R. S. Klessen , M. -M. Mac Low , E. Vazquez-Semadeni

The star-forming efficiency of dense gas is thought to be set within cores by outflow and radiative feedback. We use magneto-hydrodynamic simulations to investigate the relation between protostellar outflow evolution, turbulence and star…

Astrophysics of Galaxies · Physics 2017-10-04 Stella S. R. Offner , Jonah Chaban

High-mass stars form in protoclusters, where gravo-magnetic processes shape collapsing clouds and clumps to be elongated preferentially perpendicular to magnetic (B) fields. Yet it remains unclear whether gravo-magnetic processes still…

We use a suite of 3D simulations of star-forming molecular clouds, with and without stellar feedback, magnetic fields, and driven turbulence, to study the compression and expansion rates of the gas as functions of density. We show that,…

Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing…

Star formation is inefficient. Recent advances in numerical simulations and theoretical models of molecular clouds show that the combined effects of interstellar turbulence, magnetic fields and stellar feedback can explain the low…

Solar and Stellar Astrophysics · Physics 2020-02-12 Christoph Federrath

We present the results of a series of numerical simulations of compressible, self-gravitating hydrodynamic turbulence of cluster-forming clumps in molecular clouds. We examine the role that turbulence has in the formation of gravitationally…

Astrophysics · Physics 2009-11-10 David A. Tilley , Ralph E. Pudritz

Stars form predominantly in clusters inside dense clumps of molecular clouds that are both turbulent and magnetized. The typical size and mass of the cluster-forming clumps are $\sim 1$ pc and $\sim 10^2 - $ 10$^3$ M$_\odot$, respectively.…

Astrophysics of Galaxies · Physics 2015-05-19 Fumitaka Nakamura , Zhi-Yun Li

Stars are often observed to form in clusters. It is therefore important to understand how such a region of concentrated mass is assembled out of the diffuse medium and its properties eventually prescribe the important physical mechanisms…

Astrophysics of Galaxies · Physics 2016-06-08 Yueh-Ning Lee , Patrick Hennebelle

We study how the interaction between the streaming instability and intrinsic gas-phase turbulence affects planetesimal formation via gravitational collapse in protoplanetary disks. Turbulence impedes the formation of particle clumps by…

Earth and Planetary Astrophysics · Physics 2020-12-09 Daniel A. Gole , Jacob B. Simon , Rixin Li , Andrew N. Youdin , Philip J. Armitage

We review current understanding of star formation, outlining an overall theoretical framework and the observations that motivate it. A conception of star formation has emerged in which turbulence plays a dual role, both creating…

Astrophysics · Physics 2008-11-26 Christopher F. McKee , Eve C. Ostriker

The transport of magnetic flux to outside of collapsing molecular clouds is a required step to allow the formation of stars. Although ambipolar diffusion is often regarded as a key mechanism for that, it has been recently argued that it may…

Solar and Stellar Astrophysics · Physics 2015-05-27 E. M. de Gouveia Dal Pino , R. Santos-Lima , A. Lazarian , M. R. M. Leão , D. Falceta-Gonçalves , G. Kowal

The giant, star forming clumps in gas-rich, high redshift disks are commonly assumed to form due to gravitational instabilities, in which protoclumps have a Toomre-$Q$ parameter less than unity. However, some cosmological simulations show…

Are magnetic fields important in primordial star formation? Assuming that star formation occurs via an accretion disk that is turbulent, initially because of local gravitational instability, we calculate the disk structure for realistic…

Astrophysics · Physics 2009-11-10 Jonathan C. Tan , Eric G. Blackman

We review recent advances in the analytical and numerical modeling of the star formation rate in molecular clouds and discuss the available observational constraints. We focus on molecular clouds as the fundamental star formation sites,…

The formation of astrophysical structures, such as stars, compact objects but also galaxies, entail an,enhancement of densities by many orders of magnitude which occurs through gravitational collapse. The role played by turbulence during…

Astrophysics of Galaxies · Physics 2021-11-03 Patrick Hennebelle